title: Large IncHI2-plasmids encode extended-spectrum β-lactamases (ESBLs) in Enterobacter spp. bloodstream isolates, and support ESBL-transfer to Escherichia coli.
abstract: We investigated the prevalence of extended-spectrum β-lactamases (ESBLs) in Enterobacter spp. bloodstream isolates from 19 hospital laboratories in Norway during 2011. A total of 62/230 (27%) isolates were resistant to third-generation cephalosporins and four (1.7%) were ESBL-positive; blaCTX -M-15 (n = 3) and blaSHV -12 (n = 1). This is comparable to the prevalence of ESBLs in clinical isolates of Escherichia coli and Klebsiella pneumoniae in Norway during the same period. All ESBL-positive isolates were multidrug resistant (MDR) and harboured plasmid-mediated quinolone resistance. Three isolates supported transfer of large IncHI2-plasmids harbouring ESBL- and MDR-encoding genes to E. coli recipients by in vitro conjugation.
authors.affiliation: Reference Centre for Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway; Laboratory of Medical Microbiology, Molde Hospital, Molde, Norway.
authors.forename: E
authors.initials: E
authors.lastname: Nilsen
authors.forename: B C
authors.initials: BC
authors.lastname: Haldorsen
authors.forename: A
authors.initials: A
authors.lastname: Sundsfjord
authors.forename: G S
authors.initials: GS
authors.lastname: Simonsen
authors.forename: A
authors.initials: A
authors.lastname: Ingebretsen
authors.forename: U
authors.initials: U
authors.lastname: Naseer
authors.forename: O
authors.initials: O
authors.lastname: Samuelsen
mesh_terms: D016470:Bacteremia / Q000453:epidemiology / Q000382:microbiology*; D003227:Conjugation, Genetic; D018432:Drug Resistance, Multiple; D004754:Enterobacter / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D004756:Enterobacteriaceae Infections / Q000453:epidemiology / Q000382:microbiology; D004926:Escherichia coli / Q000235:genetics*; D022761:Gene Transfer, Horizontal; D006801:Humans; D009664:Norway / Q000453:epidemiology; D010957:Plasmids / Q000032:analysis*; D001618:beta-Lactamases / Q000235:genetics*
chemical_list: D001618:beta-Lactamases
keywords: AAC(6')-Ib-cr; CTX-M-15; Enterobacter; IncHI2; Norway; QnrB; bloodstream infection; extended-spectrum β-lactamase; plasmid